Transcript 2D First Order Flexure Analysis

2D First Order Flexure
Analysis with IDeas
B. Privári
Advanced Technology Center
Lockheed Martin, Palo Alto Ca
OPTI 521
12/02/06
Overview
• Create model in IDeas Master Series
• Reduce model into 2D planar entity
• Convert from Design into Simulation
module
• Create boundary conditions and load set
• Apply mesh and material properties
• Solve FEM
• Review post-processing and results
Model Creation
• Example is flexure design to allow
movement in xy plane only
• Model is created in version 12 of IDeas
• Analysis is done assuming no out of plane
motion
• Material analyzed is Titanium
• 2D analysis allows quicker iterations of
design before detailed study is performed
Ideas geometry in three and two
dimensional form
Reduce 3D model
• Ancillary model is created and reduced
– Perform a move/copy command on orig. part
– Original part is preserved
– Analyze ancillary part
• Unnecessary features are deleted
• Remaining geometry is planar element
design
Start FE Model
Simulation
Under Boundary
Conditions module
Create FE model
Accept default
values
Define Restraint Set
Clicking on ground
icon again brings up
this dialog box for
ground constraints
(six DOF)
Click OK and then
click on model feature
to apply ground
constraint
Load Condition
Click on force icon
to define magnitude and type of force,
then click on model feature to apply force
Vectors indicate applied forces
and constraints
Create boundary set
Combine the load set
and ground constraint
into a boundary set by
selecting the icon:
Under the management
dialog box, select the
create icon and insure
that both the load set
and restraint set are
selected. Accept by
clicking OK.
Creation of mesh elements
Boundary Conditions
Meshing
Select icon in upper left
corner and define element
size and physical property
then go to preview.
(element length was set
to 0.3 for this analysis)
Create/Confirm Element
Selecting Change
property brings up
this dialog box that
enables user to
change thickness
of element or edit
directly from element
definition icon.
Recommend other
options left at
default values.
Click OK when
changes made
(thickness was set
to 10 mm for this
analysis)
Confirm Mesh Set
Selecting preview
allows final
adjustments to the
mesh definition.
once the mesh is
defined, exit by
clicking the Keep
Mesh box.
Run Solution
Meshing
Model Solution
Start by creating a Solution
Set. This dialog box
will display after the manage
Solution Set icon is clicked
Click OK and then click
Solve under the other
arrow icon in the menu
Output Selection
While defining Solution Set
output options may be
chosen prior to solving the
model
Select the appropriate
output parameters by
clicking on the Output
Selection button
View Results
After Solve is
Performed, Click
on the Visualizer
icon
After invoking
the visualizer
several display
options including
a motion
animation are
available
Displacement
and stress are
displayed
1 N force
2.94 micron displ
7.94 MPa stress
Stress at Flexure Joint
Designer can
query model to see
where high stress
condition exists and
iterate after making
modifications to solid
model.
Spring constant may
be calculated from
the applied force and
output displacement,
assuming conditions
are below yield limit
of material.
Review Results
• Display stresses and displacements
• Confirm that design is acceptable or
determine locations or model requiring
modification.
• Re-run model with alternate load
conditions, if necessary.
• Provides quick & easy insight for designer
on how to converge to an acceptable
flexure design solution using IDeas
Acknowledgement
Special thanks to Buck Holmes of the LMATC who first stepped
author through this process